and the fbi is investigating not because of any wrongdoing, but to see if the relationship was a security risk. president obama accepted his resignation today, saying he wishes petraeus and his wife the very best at this difficult time. the bombshell came as a surprise to many on capitol hill. petraeus was highly respected by both republicans and democrats. >> for lack of a better term, petraeus is a legend. i mean, he is is one of the few generals in american history to get so much credit for so many things. >> petraeus was appointed to cia director last year. prior to that he was the commander of the wars in iraq and afghanistan. in a statement, he said after being married for over 37 years, i showed extremely poor judgment by engaging in an extramarital affair. such behavior is unacceptable both as a husband and as the leader of an organization such as ours. "nightly news" will have more on the surprise resignation coming up at 5:30. >>> just two days after being reelected, it is already hectic for president obama. not only the cia shake-up, but the president today also addressing the